Circular No. 6813
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)VARIABLE OBJECT IN DORADO
D. L. Welch, McMaster University, reports that the MACHO
collaboration (cf. IAUC 6312) has discovered what appears to be a
variable star in images obtained during monitoring of the Large
Magellanic Cloud. The object peaked in brightness around 1997 Dec.
22 UT at V = 19.0 and is located at R.A. = 4h57m46s.2, Decl. =
-67o41'08" (equinox 2000.0). The last image before outburst was
taken on Dec. 3.511, and the next observation, on Dec. 14.494,
indicates that the object had brightened by at least 1.3 mag to V
about 19.1. Eight pairs of red and blue images taken after
outburst are consistent with typical supernova fading timescales,
and there is a possible galaxy located 3" to the west of the
variable (finder charts can be obtained at
http://wwwmacho.mcmaster.ca/SN/index.html). It is therefore
possible that this variable is a supernova in a galaxy beyond the
LMC. No activity is present in 160 prior observations stretching
back two years.
MXB 1730-335
R. Rutledge, University of California at Berkeley; C. Moore,
Kapteyn Institute; D. Fox and W. Lewin, Massachusetts Institute of
Technology; and J. van Paradijs, University of Amsterdam and
University of Alabama at Huntsville, report the discovery of a
radio transient with flux density correlated with the RXTE/ASM x-
ray flux of the rapid burster MXB 1730-335 (cf. IAUC 6409, 6506),
in five observations at the Very Large Array at 8.0 GHz during the
Dec. 1996 and June/July 1997 outbursts. The position of the radio
source is R.A. = 17h33m24s.61, Decl. = -33o23'19".8 (equinox
2000.0; uncertainty 0".1). Details for a proposed radio campaign
during the next outburst (expected in the next few months) will be
given at http://astron.berkeley.edu/~rutledge/rb.html.
COMET C/1997 S2 (SOHO)
Further to IAUC 6811, another comet, tail-less and with peak
mag about 7.5, has been found by D. A. Biesecker in the SOHO-LASCO
archive, bringing the total number of SOHO comets to 40. Details
are on MPEC 1998-B22.
1997 UT R.A. (2000) Decl.
Sept.25.442 11 44.9 - 2 15
(C) Copyright 1998 CBAT1998 January 27 (6813) Daniel W. E. Green